Matthew Jackson
9f25a4c454
Resolution::pixels() returned (0, 0) for Unknown, and the MP4 sink wrote it verbatim into tkhd (ISO/IEC 14496-12 8.3.2) and VisualSampleEntry (12.1.3). Both fields are MANDATORY there, so unlike Matroska — which omits the optional PixelWidth/PixelHeight elements — MP4 has nothing to leave out. The result was a structurally complete file that passes every container check, declares a 0x0 video track, cannot be rendered, and is written with no error anywhere. WHY IT WAS POSSIBLE, which is the part worth keeping: pixels() previously fabricated 1920x1080 for Unknown. That was wrong but playable, so this sink never needed a guard and the absence of one was invisible. Changing the sentinel to (0, 0) moved the defect instead of removing it — a zero PAIR still reads as a usable value, so the sink stored it and serialised it. The accessor's doc comment then ENUMERATED the callers it believed were safe: "the Matroska sink omits the optional elements, the VobSub writer omits its size: line, and no caller divides by either dimension." Two of those three are true. MP4 was not on the list because MP4 has no guard at all, and a prose list cannot enforce itself. mkv.rs's own comment even states the principle — "the check belongs in the one accessor rather than in each caller that remembered to write it" — and labels/mod.rs still carried its own duplicate Unknown test long after the accessor took that job over. So: pixels() now returns Option. Not because Option is tidier, but because every caller genuinely needs a DIFFERENT answer and the compiler is the only thing that reliably makes them choose one. Matroska and the metadata sinks take unwrap_or((0, 0)) with the reason stated at each site; the VobSub path degrades to a palette-only .idx; MP4 fails with E_MP4_UNKNOWN_RESOLUTION (9055). Six call sites, not the five my first grep showed — I piped it through `head` and acted on a truncated list. The compiler caught the sixth. That is the same mistake as trusting a lens that reported silence.
libfreemkv
Rust library for 4K UHD / Blu-ray / DVD optical drives. Drive access, disc scanning, stream labels, AACS decryption, CSS decryption, KEYDB updates, and content reading in one crate. Drive-level unlocking is handled internally; consumers work with disc access and decryption only.
DVDs (CSS) decrypt out of the box. Blu-ray and UHD (AACS) require a keydb.cfg (default ~/.config/freemkv/keydb.cfg) supplying disc-specific volume unique keys; no AACS key material is compiled in.
12+ MB/s sustained read speeds on BD. Drive prep (init()) handles unlocking internally via the freemkv-unlock crate — clients never see it; when no drive unlock applies, the library rips via the host-certificate AACS handshake.
Multi-lingual by design — the library outputs structured data and numeric error codes, never English text. Build any UI or localization on top.
Part of the freemkv project.
Install
Consumed by git tag (not published to crates.io):
[dependencies]
libfreemkv = { git = "https://github.com/freemkv/libfreemkv", tag = "vX.Y.Z" }
Quick Start
use libfreemkv::{Drive, Disc, ScanOptions};
use std::path::Path;
// Open drive — identified via INQUIRY
let mut drive = Drive::open(Path::new("/dev/sg4"))?;
drive.wait_ready()?; // wait for disc
drive.init()?; // unlock + prep (handled internally)
drive.probe_disc()?; // probe disc surface for optimal speeds
// Scan disc — UDF, playlists, streams, AACS (all automatic)
let disc = Disc::scan(&mut drive, &ScanOptions::default())?;
for title in &disc.titles {
println!("{} — {} streams", title.duration_display(), title.streams.len());
}
// Stream pipeline — read PES frames from any source, write to any output
let opts = libfreemkv::InputOptions::default();
let mut input = libfreemkv::input("iso://Disc.iso", &opts)?;
let title = input.info().clone();
let mut output = libfreemkv::output("mkv://Movie.mkv", &title)?;
while let Ok(Some(frame)) = input.read() {
output.write(&frame)?;
}
output.finish()?;
Multi-pass recovery rip
Recovery moved OUT of this crate in 1.6.0. The sweep/patch strategy, the
ddrescue mapfile, damage classification and the multipass loop now live in the
freemkv-engine crate as freemkv_engine::recovery::{copy, sweep, patch}.
libfreemkv keeps the layers underneath: the raw single-shot read
(Drive::read) and the SCSI-fact translation (SenseFamily) that the engine's
strategy is built on. The dependency runs engine → libfreemkv, so this crate
cannot call into it; front-ends get recovery from the engine directly. See
docs/rip-recovery.md for what stayed here.
What It Does
- Drive access — open, identify, internal unlock + prep, speed control, eject
- 12+ MB/s reads — auto-detects kernel transfer limits, sustained full speed
- Disc scanning — UDF 2.50 filesystem, MPLS playlists, CLPI clip info
- Stream labels — 5 BD-J format parsers (Paramount, Criterion, Pixelogic, CTRM, Deluxe)
- AACS decryption — transparent key resolution and content decrypt (1.0 + 2.0 bus decryption)
- KEYDB updates — download, verify, save from any HTTP URL (zero deps, raw TCP)
- Content reading — adaptive batch reads with automatic decryption
- Stream I/O — unified stream pipeline for reading and writing any format
Streams
| Stream | Input | Output | Transport |
|---|---|---|---|
| DiscStream | Yes | -- | Optical drive via SCSI |
| IsoStream | Yes | -- | Blu-ray ISO image file (read via stream pipeline; written by freemkv_engine::recovery) |
| MkvStream | Yes | Yes | Matroska container |
| M2tsStream | Yes | Yes | BD transport stream with FMKV metadata header |
| NetworkStream | Yes (listen) | Yes (connect) | TCP with FMKV metadata header |
| StdioStream | Yes (stdin) | Yes (stdout) | Raw byte pipe |
| NullStream | -- | Yes | Discard sink (byte counter for benchmarks) |
Streams implement a single unified pes::Stream trait (re-exported as PesStream) exposing read() and write() on one type. input() / output() resolve URL strings to PES stream instances. All URLs use the scheme://path format — bare paths are rejected.
Keys
DVDs (CSS) decrypt out of the box, with no external key file needed.
Blu-rays and UHD (AACS) require a keydb.cfg at ~/.config/freemkv/keydb.cfg (or passed via ScanOptions). No AACS key material is compiled into the binary.
Architecture
Drive — open, identify, init, single-shot read
├── ScsiTransport — SG_IO (Linux), IOKit (macOS), SPTI (Windows)
└── unlock_bridge — private seam to the freemkv-unlock crate
(firmware / AACS cert / CSS bus-auth unlockers)
Disc — scan titles, streams, AACS/CSS state
├── UDF reader — Blu-ray UDF 2.50 with metadata partitions
├── MPLS parser — playlists → titles + clips + streams
├── CLPI parser — clip info → EP map → sector extents
├── IFO parser — DVD title sets, PGC chains, cell addresses
├── Labels — 5 BD-J format parsers (detect + parse)
├── AACS — key resolution + content decryption
├── CSS — DVD CSS (bus auth → player-key disc crack → known-plaintext title-key attack)
└── KEYDB — download + verify + save
Streams — unified PES pipeline
├── PesStream — pes::Stream: one trait, read()/write() PES frames
├── DiscStream — sectors → decrypt → TS demux → PES
├── IsoStream — ISO file → decrypt → TS demux → PES
├── MkvStream — MKV mux/demux
├── M2tsStream — BD transport stream
├── NetworkStream — TCP with FMKV metadata header
├── StdioStream — stdin/stdout pipe
└── NullStream — discard sink
See docs/ for detailed technical documentation on each module.
Error Codes
All errors are structured with numeric codes. No user-facing English text — applications format their own messages.
| Range | Category |
|---|---|
| E1xxx | Device errors (not found, permission) |
| E2xxx | Profile errors (unsupported drive) |
| E3xxx | Unlock errors (failed, signature) |
| E4xxx | SCSI errors (command failed, timeout) |
| E5xxx | I/O errors |
| E6xxx | Disc format errors |
| E7xxx | AACS errors |
| E8xxx | KEYDB update errors |
| E9xxx | Stream / mux errors (URL, PES, ISO, pipeline, demux) |
Platform Support
| Platform | Status | Backend |
|---|---|---|
| Linux | Supported | SG_IO ioctl |
| macOS | Supported | IOKit SCSITask |
| Windows | Supported | SPTI |
Contributing
Run freemkv info disc:// --share with the freemkv CLI to capture your drive's identity for contribution. Drive-unlock profiles are maintained in the freemkv-unlock repository.
License
MIT